Most buildings require some level of access control to prevent parts of the building from being accessible to the public. In many buildings this access control is included at the entrance to the building itself. However, many larger buildings have portions of the building that are accessible to the public, while other parts are private and require a certain level of security. It is particularly common for the ground floor or lobby of a large building to be open to the public, but access to the upper floors of the building to be private and secured. To limit access or keep the upper floors of the building secure, many buildings of this type entirely restrict non-authorized individuals from accessing the elevators. To ensure that non-authorized individuals are unable to access the elevator, the building may have barriers or security officers, or a combination of each. Neither of these solutions is ideal.
Often times tenants of buildings find the use of restrictive barriers to be unsightly. Moreover, depending on the type used, the barriers may hinder foot traffic into and out of the building. To limit the problems associated with restrictive barriers, they are typically kept as small as possible. However, small barriers, for example short turnstiles, are not particularly effective at keeping access to an area restricted. A person determined to enter the restricted area may, for example, jump over the turnstiles or circumvent the barrier in another manner. Accordingly, such barriers typically are coupled with security officers.
However, a team of security officers, though effective, can be expensive to maintain. Thus, there is a need for an access control system that limits access to the certain floors of a building without requiring restrictive barriers or a large number of security officers.
International Patent Application Publication No. WO 2010/002378 A1 discloses a security-based elevator control method that operates elevator cars based in part on the determination of a security violation involving one of the elevator cars. The disclosed method uses sensors that detect the presence of an unauthorized user as the user enters the elevator car by crossing a threshold between the landing and the car. A sensor is placed at each elevator car opening. This method requires that the unauthorized person be wearing a detectable identification tag that can be identified by the sensor, such as the identification tag on an infant or medical patient, or a tracking device on an incarcerated individual. Alternatively, an authorized individual, such as a receptionist, may note the presence of an unauthorized user within an elevator car and notify the security-based system. Although a system of this type may be effective at containing known unauthorized persons that are tagged with identification or tracking devices, it is not capable of preventing unknown unauthorized persons from using the elevator system.